Highly Loaded P/M Gears Produced by Selective Surface Densification

This paper reviews the current development status of highly loaded P/M gears. It is shown that surface densified P/M steels can sustain typical stresses in gears generated by bending of the tooth and rolling contact fatigue at the tooth flank. Specifically, the design of the preform and the corresponding density distribution in the gear after rolling is described. Results from load tests of various P/M steels which simulate tooth root and flank loading are discussed and compared to a standard gear steel (16MnCr5). Finally, it is shown that P/M gears manufactured by selective surface densification combine mechanical performance with a significant cost savings potential.